A face shield which can protect the face while a visual field is ensured has been conventionally used in order to protect the face from a flying object to the face in a surgery or the like.
For example, a face shield has been proposed which has a structure where a transparent plastic film is attached to a face mask as an eye shield (see, for example, PTL 1).
A surgical lighting system very high in intensity is used in an operating room where a surgery is conducted, and a face shield in such a lighting system is demanded to be a transparent body having high antireflection properties. In addition, mechanical strength such as scratch resistance is also demanded.
As the transparent structure having antireflection properties, a transparent structure is known which has a fine depression and protrusion structure made of a cured product of an active energy ray curable composition (see, for example, PTLs 2 and 3).
PTL 2 discloses a transparent structure where the water contact angle on the surface of a depression and protrusion layer is 25° or less and the elastic modulus of the surface of a depression and protrusion layer is 200 MPa or more to thereby allow the structure to have antifouling properties and abrasion resistance.
In addition, PTL 3 discloses a transparent structure where a polymerizable composition containing 24.8% or more of a tri- or higher functional acrylate compound and 37.2% or more of polyethylene glycol diacrylate is polymerized to form a structure, and the storage elastic modulus at 180° C. or more is 0.5 GPa or more to thereby allow the structure to have antifouling properties and abrasion resistance.
In consideration of putting a face shield or the like to practical use as a medical face protection mask or the like, however, the above-mentioned techniques disclosed cannot be said to be sufficient.
In order to provide a transparent structure suitable for production and use of a medical face protection mask, the transparent structure is required to not only have antifouling properties and abrasion resistance, but also have the following properties: (1) antifogging properties; (2) an enhancement in use selectivity of a surface protection film and (3) prevention of an adverse effect by the surface protection film in use of the surface protection film in production and processing of the medical face protection mask; and (4) crack resistance which causes no cracking in providing a mask shape by punching.
There has not been provided a transparent structure which satisfies all properties including not only antifouling properties and abrasion resistance, but also the above properties (1) to (4), and a transparent structure is demanded which can be put into practical use for a medical face protection mask and the like.